Manufacturing process for aluminous cements



Patented June 1, 1929.

UNITED STATES PATENT OFEl-fiE.

ERNEST MARTIN, on AIX, FRANCE. 7

"MANUFACTURING PROCESS non ALUMINOUS cEMEiws.

No Drawing. Application filed April 27, 1926,.Scria1 No. 105,016, and in France April 30, 1925.

' The different processes hitherto employed for the manufacture of aluminous ce ments consist in burning mixtures of alumlnous materials with lime. I

The burning is accomplished either by melting, or. by clinkerizing or otherwise avoiding the melting point.

The objectfof the invention is to provide a process which consists in the incorporation in the known mixture of alumina and lime of a small quantity of certain salts adapted to facilitate the formation of hydraulically bindingproducts,

The salts to be. utilized in this case are: alkaline salts, calcium chloride, calcium fluoride and cryolite.

' In the alkaline salts viz, chlorides, sul phates, carbonates, silicates and aluminates,

sodium chloride is the salt of this class ing point. It is also possibleto burn while melting or clinkerizing or avoiding any melt Vhen during the burning alkalin e salts are used, mixed aluminates, calcic and alkaline, constituting perfect hydraulic products are produced.

The. alkaline salts retard the melting, because aluminates containing alkalis are not so fusible as the simple calcic aluminates. In other words, by reason of theaddition of alkaline salts to the initial mixture, the

fusion of the mass takes place at a higher temperature because of the formation of aluminates containing sodium,"it being well known that sodium aluminates are infusible at temperatures used in the manufacture of aluminous cement.

' By the employment of calcium chloride, or

preferably fluoride it is possible to easily ob-.

tain the clinkerization which is very difficult to obtain without the 'use of said: salts. The clinkers are not hard to crush and give after pulverization a very rapidly binding cement in which the hydration of the whole is complete, without leaving inert particles as happens with melted cements reaching the melting point.

disclosed for instance in U.

clinkerizing or; preventing the mixture from By means of the incorporated salts it is possible to obtain in a single burning below :the melting point aluminous cements of a clear color which harden very r'apidlyi.

The color of cements, clinkerized. or melted changes from light gray to black-gray, the binding being then, slower than in the case of unmelted'cements. i

By incorporating in the mixtures at sufli- .draulically binding products and without --cient quantity of lime to obtain ferric by I I reachingthe melting point, the cement is richer in hydraulically bindin products as p Patent No. 1,586,099, May 25, 1926. e v v The added salts equally facilitate the reenough.

The aluminous cements prepared as above described produce mortars which are not decomposed by, sea water or hard waters. Mortars obtained with unmelted cements may be dipped a few minutes after preparation. I declare that what I claim is 1. In. the manufacture of aluminous ce ment, the step of incorporating as a catalyz er a small proportion at least of an alkaline salt to the aluminous cement forming mixture before heating the same whereby the formation of hydraulic aluminates is facilitated. y

B 2. In the manufacture of aluminous cement, the step of incorporating with the aluminous cement forming mixture before heating of a catal'yzer consisting of a small proportion at least of alkaline haloid whereb to facilitate formation of hydraulic alul minates. p 3. In the manufacture of'aluminous cement, the step of incorporating with the s5 actions in this case and a single burning is alnminous cement forming mixture before heatingof a cat-alyzer consisting of a small proportion at least of an alkaline chloride whereby to facilitate formation of hydraulic aluminates.

4. In the mannfactilre of alumino'us cement, the step of incorporating with the aluminous cementfiforming mixture before heating of a ca-talyzer consisting of a small proportion at least of chloride of soda-l name to this specification.

ERNEST MARTIN. 

